I have a nextbase in the car, just usb plugin ... i know typical spark its not hardwired yet lol.
Its saved me a few times ,with road rage incidents, as I can point to the camera and say see you on youtube. your mad drivers usually clear off at that point.
things to be aware of :
some have gps and can work out your speed at time of any accidents. If you submit the sd card to your insurance company after a bump and they look at your movements,they might see your bad driving habits ie speeding a lot.
Some have voice recording and record what is said within the car, this can be switched off , but you need to switch off.
I think its been money well spent